In Greek mythology Ino (/ˈaɪnoʊ/ Greek: Ἰνώ Ancient: [iːnɔ̌ː]) was a mortal queen of Thebes, who after her death and transfiguration was worshiped as a goddess under her epithet Leucothea, the "white goddess." Alcman called her "Queen of the Sea" (θαλασσομέδουσα), which, if not hyperbole, would make her a doublet of Amphitrite.
In her mortal self, Ino, the second wife of the Minyan king Athamas, the mother of Learches and Melicertes, daughter of Cadmus and Harmonia and stepmother of Phrixus and Helle, was one of the three sisters of Semele, the mortal woman of the house of Cadmus who gave birth to Dionysus. The three sisters were Agave, Autonoë and Ino, who was a surrogate for the divine nurses of Dionysus: "Ino was a primordial Dionysian woman, nurse to the god and a divine maenad" (Kerenyi 1976:246).
Maenads were reputed to tear their own children limb from limb in their madness. In the back-story to the heroic tale of Jason and the Golden Fleece, Phrixus and Helle, twin children of Athamas and Nephele, were hated by their stepmother, Ino. Ino hatched a devious plot to get rid of the twins, roasting all the crop seeds of Boeotia so they would not grow. The local farmers, frightened of famine, asked a nearby oracle for assistance. Ino bribed the men sent to the oracle to lie and tell the others that the oracle required the sacrifice of Phrixus. Athamas reluctantly agreed. Before he was killed though, Phrixus and Helle were rescued by a flying golden ram sent by Nephele, their natural mother. Helle fell off the ram into the Hellespont (which was named after her, meaning Sea of Helle) and drowned, but Phrixus survived all the way to Colchis, where King Aeetes took him in and treated him kindly, giving Phrixus his daughter, Chalciope, in marriage. In gratitude, Phrixus gave the king the golden fleece of the ram, which Aeetes hung in a tree in his kingdom.